Production of valuable products from petroleum hydrocarbons



Patented Dec. 1a, 1938 PRODUCTION or VALUABLE mwnUc'rs mom ra'rnomum nrnnocnnnons Raphael my, Cranford, and Charles A. Cohen,

Elizabeth, N. .L, assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application March 30, 19.34,

Serial No. 718,200

4 Ciaims. (or. 260- 170) This inventionrelates to improvements in the manufacture and production of valuable products from petroleum hydrocarbons and relates par ticularly to a process of treating with solvents distillates obtained from the products formed by cracking petroleum hydrocarbons.

The petroleum distillates obtained from the products formed by vapor phase cracking of petroleum hydrocarbons'contain saturated and un- 10 saturated compounds together with hydrogen.- Two series of unsaturated compounds are found present in substantial quantities, i. e., olefines and dioleiines. The dioleflnes' readily polymerize and form gums and therefore are generally removed before the distillates are marketed. The 'percentage of dioleflnes present varies from. about 1% in products formed by liquid phase cracking to about 10% in products formed by vapor phase cracking.

According to the present invention, the diolefines and a fraction of the oleflnes are removed from the petroleum distiilates by the use of solvents, recovered and used in the preparation of valuable products by polymerizing with the aid of a metallic halide or other catalysts to produce synthetic resins, oils, thickeners, lubricants, drying oils, and the like. I

An object of this invention is to provide a process for solveht treating the petroleum distillates shaking one of the above solvents or a mixture;

of the solvents with the cracked petroleum distillate, 'or otherwise bringing the solvents and distillate into intimate contact, allowing the resuiting mixture to settle and stratify and withdrawing the solvent layer. The olefines' and diolefines dissolved 'in the solvent are then separated from the solvent by heating, dilution or the like. When gaseous mixtures containing unsaturated compounds are to be treated, the oleflnes anddiolefines may be dissolved in the solvents by bubbling the gaseous mixture through one or more bodies of the organic solvents. The olefines and dioleflnes are their expelled from the organic solvents by the application of heat and segregated. The contacting of the organic solvents and the cracked petroleum distillates may be made at temperatures from 30 to 100' 0., preferably etc. into the lower part of the. absorber.

These orroom temperature, though lower temperatures are desirable when treating gaseous mixtures. Atmospheric pressures may be used, though higher pressures are desirable when gaseous olefines and .diolefines are being recovered to maintain the extract in the liquid phase. A countercurrent method of treating may also be used such as by passing the product into an intermediate part of an absorber, passing the solvent into the upper portion of the absorber and a volatile saturated hydrocarbon such as propane, butane, hexane,

solvent, on coming in contact with the petroleum distillate, mechanically holds in suspension a fraction of saturated hydrocarbons. It is desirable to remove these saturated hydrocarbons method of extraction may be either batch or continuous. I

The separated mixtures of olefln'es and diolefines that are preferably extracted by these solvents in a. diolefine-olefine ratio greater than one, may then be contacted with a catalyst such as anhydrous aluminumchloride or boron fluoride. Suitable cooling means are provided as the reaction is a'rapid one with the evolution of heat. ,The'reaction is controlled by adding the catalyst slowly-to th'mixture of olefines and dioleflnes. A resin is formed whose carbon-hydrogen ratio varies with the amount of oleflne preseut. The

amount ofolefine present governs the hardness of the resin formed as where more olefines are present a softer resin is produced. Other catalysts such as sulfuric acid, phosphates, etc., at higher temperatures may also be used. The dioleflnes present in the extracted mixture maybe further separated from the olefines bymeans of substances such as maleic anhydride or cuprous chloride with ammonium chloride, and used in "thepreparation of resins. The concentrate may be usedas'a source of high concentration of dioleflnes to-be used for rubber production, or any reactions which may be developed for dioleflne.

The following table illustrates the various proportions of olefines and diolefines that are removed by the use of various solvents:

Volume to volume extraction 0! 1% of solution of pentene and 1% solution oi'isoprene in a gasoline solution Solvent Percent oi Percent oi pentene Y isoprcne removed removed Triethylcitrate 23. 0 34. 0 Dimethyl phthalate 25. 0 35. 0

The.

Mixtures of the above solvents may also be used to' obtain a mixture of oleflnes and (Hole-,- fines of the desired proportions.

The foregoing description is merely illustrative and alternative arrangement may be made within the scope of the appended claims in which it is our intention to claim all novelty as broadly as the prior art permits.

We claim:

1. A process for the separation of olefines and dioleflnes from other substances which comprises contacting at temperatures from minus 30 C. to 100 C. a mixture of olefinesand diolefines and other hydrocarbons with dimethyl phthalate, separating the solvent, and recovering olefines and dioleiines from the separated solvent.

2. A process for the separation of olefines and dioleflnes from other substances which comprises contacting at temperatures from minus 30 C. to 100 C. a mixture of oleflnes and diolefines and other hydrocarbons with dimethyl phthalate, separating the solvent, treating the olefines and diolefines in the separated solvent with a condensing agent to form resins, and recovering the resins.

3. A process of. separating and recovering constituents of petroleum products which comprises intimately contacting a petroleum product in liquid form with dimethyl phthalate, under circumstances permitting development of a twophase liquid and separating the two phases by gravity.

4. A process according to claim 3 in which the petroleum product is a cracked stock.

RAPHAEL ROSEN.

CHARLES A. COHEN. 

